/*
 * gybon - Core modules for Google Yahoo Rich Application Framework
 *
 * Copyright (c) 2009, Yves Cuillerdier
 * All rights reserved.
 * 
 * This software is licensed under the new BSD License:
 * 
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, 
 * this list of conditions and the following disclaimer.
 * 
 * Redistributions in binary form must reproduce the above copyright notice, 
 * this list of conditions and the following disclaimer in the documentation 
 * and/or other materials provided with the distribution.
 * 
 * Neither the name of the author nor the names of its contributors may 
 * be used to endorse or promote products derived from this software without 
 * specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
 * POSSIBILITY OF SUCH DAMAGE.
 * 
 * @version 0.2.0
 */
package gyraf.wrapper.client.event;

import com.google.gwt.core.client.JavaScriptObject;

/**
 * Utility class to add listeners to YUI classes.
 * <p>
 * There exists many YUI paradigm for attaching events to objects:
 * <ul>
 * <li><tt>element.event.subscribe(handler)</tt>: Events are attached to
 * elements and subscribe</li>
 * <li><tt>element.addListener(event,handler)</tt>: Listeners are added to
 * element for given event</li>
 * </ul>
 * This class provides useful methods for "Gluing" elements with YUI JavaScript.
 */
public class EventListenerUtil {

	/** Static utility class */
	private EventListenerUtil() {
		// cannot be instantiated
	}

	/**
	 * Use element.eventName.subscribe to listen.
	 * 
	 * @param element
	 *            the element
	 * @param event
	 *            the event
	 * @param handler
	 *            the handler
	 */
	public native static void elementEventSubscribe(JavaScriptObject element,
			String event, JavaScriptObject handler) /*-{
		element[event].subscribe(handler);	
	}-*/;

	/**
	 * Use element.eventName.unsubscribe to stop listening.
	 * 
	 * @param element
	 *            the element
	 * @param event
	 *            the event
	 * @param handler
	 *            the handler
	 */
	public native static void elementEventUnsubscribe(JavaScriptObject element,
			String event, JavaScriptObject handler) /*-{
		element[event].unsubscribe(handler);	
	}-*/;

	/**
	 * Use element.addListener or element.on to listen.
	 * 
	 * @param element
	 *            the element
	 * @param event
	 *            the event
	 * @param handler
	 *            the handler
	 */
	public native static void elementEventOn(JavaScriptObject element,
			String event, JavaScriptObject handler) /*-{
		element.addListener(event,handler);	
	}-*/;

	/**
	 * Use element.removeListener to stop listening.
	 * 
	 * @param element
	 *            the element
	 * @param event
	 *            the event
	 * @param handler
	 *            the handler
	 */
	public native static void elementEventOff(JavaScriptObject element,
			String event, JavaScriptObject handler) /*-{
		element.removeListener(event,handler);	
	}-*/;
}
